The present invention relates to a radio terminal for browsing the Internet. It particularly relates to increasing the functionality of such a terminal.
Mobile phones are becoming widely used, as they provide security, mobility and flexibility. Recently the popularity of the Internet has increased among the general population. The Internet can be browsed using a so-called browser application, which provides an easily usable visual interface. It would be particularly desirable to combine the hand held nature of a mobile phone and its associated portability with the ability to browse the Internet. The wireless application protocol (WAP) has been developed with this purpose in mind. It allows a radio handset to communicate with a transceiver at an internet gateway and accesses the Internet through a radio link. A Wireless Application Environment which forms an upper layer of the WAP stack includes a microbrowser. The browser uses wireless mark-up language (WML) and a lightweight mark-up language, WMLScript a lightweight scripting language. WML implements a card and deck metaphor. The interaction of the browser and user is described in a set of cards which are grouped together into a document commonly referred to as a deck. The user navigates to a card in a deck, reviews its content, and then navigates to another card in the same deck or in a different deck. Decks of cards are transferred from origin servers as needed.
A desktop computer or the like, has until now been the standard device for accessing the World Wide Web. The computer generally has a display, a cursor control and selecting device such as a mouse and a keyboard. When using a device to browse the World Wide Web, the device generally exchanges information with the Internet gateway over a fixed high band-width link. The device acts as a client and the Internet as a server. The browser can access an ‘item’ of content using a URL. This item allows access to further items of content, each of which comprises content or means for linking to content. Typically content is downloaded from the Internet to the device to allow a browser application in the device to display one page having a number of icons which are ‘active’. Choosing and selecting an icon using the cursor control and selection device activates a ‘link’ to another defined page. The browser application requests this page from the Internet gateway acting as server. Content downloaded from the Internet to the device allows the browser application to display the page, which has been linked to. This page may in turn display ‘active’ icons for user selection. The browser application mediates between the user and the Internet. It sends requests to the Internet and receives content therefrom.
The content received from the Internet may be instructions allowing the browser application to recreate a page with the correct links. It may, however, be content which cannot be processed by the browser application but which requires a separate, different application such as an email application, a news reading application, etc. Portable terminals and hand held devices in particular have limited processing and memory resources. It is desirable to maximise their resources by integrating these applications with the browser without significantly increasing the complexity of the browser application itself. Such integration may require modification of the Wireless Application Protocol, and in particular modification of WML and/or WMLScript.
It is desirable to use a browser without unduly increasing the traffic between the server and terminal.
This could be done by so called cache browsing, which means that a copy of the content fetched from a server is stored in a memory in the phone. The cache browsing for mobile computing is disclosed e.g. in the article “Cache Management for Mobile Databases”, Chan, B. Y. et al., Proceedings: 14th International Conference on Data Engineering 1998, pages 54-63, and “Overcoming the Network Bottleneck”, Ebling, M. R. et al., Conference: Workshop on Mobile Computing 1995, pages 34-36. However, the handling of cache data described in these two documents requires some kind of user interaction.